Looking for an apt. or hotel in London this summer

We go to London often with our teens and used to live there. We've done Airbnbs, bed and breakfasts etc, but have found the best value to be the PremierInn chain (https://www.premierinn.com/gb/en/hotels/england/greater-london.html). It's nothing fancy but they are quiet, the beds are really good quality and they have "family rooms" with a third or fourth bed big enough for a teen. (Their new hub hotels are super small/no frills, but their regular hotels are quite spacious and have full restaurants etc.) We've stayed at their Euston, Kings Cross, and Victoria hotels for around 75-85 pounds a night, and they have hotels all over London. One time we splurged on an Airbnb for 250 pounds a night and it ended up being a huge pain to get the key, noisy etc and we wished we had just done PremierInn and saved a bundle to then spend eating out and going to theater etc! PremierInns don't show up on Hotels.com and the other search aggregators. Good luck!

The University of London offers B&B-style accommodations over the summer for short-term stays. I’ve stayed in the the dorms twice since studying there for a year in college and have had good experiences. It’s a good deal for basic accommodations in a great location. And, bonus, your son can experience dorm life (and dorm food!) well before college apps are due! More info: https://housing.london.ac.uk/find-accommodation/short-term-housing/university-halls-residence

I've been to London a few times with teenagers and I'm going again this summer.  If you're looking for a hotel, I highly recommend using Tripadvisor.  Start with the most highly ranked ones and scroll down till you find one in your price range. We found a hotel we really liked this way - we've stayed there twice. It's called Park Plaza County Hall and it's a block from the London Eye. Walkable to everywhere, got a room with a bed and sofabed which is great with teens, plus good breakfast.  This summer we will be using a booking agency called Veeve.com to rent a flat because we needed 4 bedrooms. So far so good, but no direct experience yet. I like the idea of a local agent rather than arrangements with individuals on AirBnB. I've used AirBnB a lot domestically, and one time in Scotland which turned out fine, but I have heard too many horror stories from friends who ended up in disastrous AirBnB rentals abroad with no one local to help, so I've shied away from those.  Have a wonderful trip!  I hope Brexit gets sorted out before we go!